mesh-tools/node-tools/internal/firstview/firstview_test.go

package firstview

import (
	"context"
	"encoding/json"
	"errors"
	"os"
	"slices"
	"strings"
	"sync"
	"testing"
	"time"

	condseat "git.novox.be/novox/mesh-contracts/health-and-repair/go/seats/meshconditions"
	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-contracts/go/clients/meshcatalogclient"
	catalogseat "git.novox.be/novox/mesh-delivery/modules/mesh-delivery-contracts/go/seats/meshcatalog"
	delivery "git.novox.be/novox/mesh-delivery/modules/mesh-delivery-contracts/go/seats/meshdelivery"
	"git.novox.be/novox/mesh-sdk/go/views"

	"github.com/novox/mesh-tools/node-tools/internal/bus"
)

// owners is the four owners' first-view tools as a test answers them: a state's values at a revision, or nothing while down.
type owners struct {
	mu      sync.Mutex
	down    bool
	state   map[string]map[string]string // tool → key → value
	rev     map[string]uint64
	asked   map[string]int
	deliver func(bus.Envelope) error
	finds   map[string]bool
	// catalog is the revision of the watched branch main the seat mesh-catalog answers, and modules its entries
	catalog int64
	modules []string
	// holder is the module among them that claims the assigner seat
	holder string
}

func newOwners() *owners {
	return &owners{state: map[string]map[string]string{"assignments": {"anchor": `{"p":1}`}, "seat-holders": {"seat": `{"h":1}`}},
		rev: map[string]uint64{"assignments": 4, "seat-holders": 2}, asked: map[string]int{}, finds: map[string]bool{},
		catalog: 3, modules: []string{"web", fixtureHolder}, holder: fixtureHolder}
}

// Write and Clear are the runner's finding writer in a test: the findings written and not cleared, by their key.
func (o *owners) Write(_ context.Context, f condseat.Finding) error {
	o.mu.Lock()
	defer o.mu.Unlock()
	o.finds[views.FindingKey(f.Scope, f.ID, f.Kind)] = true
	return nil
}

func (o *owners) Clear(_ context.Context, scope, id, kind, _ string) error {
	o.mu.Lock()
	defer o.mu.Unlock()
	delete(o.finds, views.FindingKey(scope, id, kind))
	return nil
}

func (o *owners) ask(address string, _ any) (json.RawMessage, error) {
	o.mu.Lock()
	defer o.mu.Unlock()
	tool := address[strings.LastIndex(address, ".")+1:]
	o.asked[tool]++
	if o.down {
		return nil, errors.New("503 no responders")
	}
	switch address {
	case "seat:mesh-delivery.source":
		return json.Marshal(delivery.SourceAnswer{Branches: []string{"main"}})
	case "seat:mesh-catalog.registrations":
		return json.Marshal(catalogseat.RegistrationsAnswer{Registrations: []catalogseat.Registration{}})
	case "seat:mesh-catalog.revision":
		a := catalogseat.RevisionAnswer{Revision: &catalogseat.CatalogRevision{Revision: o.catalog, Kind: meshcatalogclient.KindTrunk, Branch: "main"}}
		for _, m := range o.modules {
			e := catalogseat.CatalogEntry{Module: m, Manifest: map[string]any{"module": m, "tools": []string{m + "_check"}}}
			if m == o.holder {
				e.Serves = []string{AssignerSeat + ".assignments", AssignerSeat + ".seat-holders"}
			}
			a.Entries = append(a.Entries, e)
		}
		return json.Marshal(a)
	}
	vals := map[string]json.RawMessage{}
	for k, v := range o.state[tool] {
		vals[k] = json.RawMessage(v)
	}
	return json.Marshal(views.Answer{V: 1, Owner: "o", State: tool, Revision: o.rev[tool], Created: time.Unix(1000, 0).UTC(), Values: vals})
}

func (o *owners) say(t *testing.T, state, key, value string, revision uint64, gap bool) {
	t.Helper()
	ev := views.Event{V: 1, Owner: owner(state), State: state, Key: key, Revision: revision, Created: time.Unix(1000, 0).UTC(), Gap: gap}
	if value != "" {
		ev.Value = json.RawMessage(value)
	}
	raw, _ := json.Marshal(ev)
	if err := o.deliver(bus.Envelope{Key: ev.Owner + ".views." + state, Body: raw}); err != nil {
		t.Fatal(err)
	}
}

// fixtureHolder is the module the fixture catalog half says claims the assigner seat: no name is in the code.
const fixtureHolder = "assigner-fixture"

func owner(state string) string { return fixtureHolder }

func eventually(t *testing.T, what string, ok func() bool) {
	t.Helper()
	for end := time.Now().Add(3 * time.Second); !ok(); time.Sleep(5 * time.Millisecond) {
		if time.Now().After(end) {
			t.Fatal(what)
		}
	}
}

// issue 1966 TLS-5 (ADR 0615 §2, §4, §5, §6): the runner holds the four states from the owners' first views and their
// events alone; nothing is claimed of a state not yet answered; a gap asks the first view once more; an owner that stays down
// past the bound is a finding, cleared by the answer; the status and the hand ask show them.
func TestTheRunnerHoldsTheFourStatesFromTheOwnersFirstViewsAndTheirEvents(t *testing.T) {
	o := newOwners()
	o.down = true
	var logs []string
	var lmu sync.Mutex
	deps := Deps{Module: "node-tools", Ask: o.ask, Bound: 30 * time.Millisecond, Wait: 10 * time.Millisecond,
		Consume:  func(deliver func(bus.Envelope) error) (func(), error) { o.deliver = deliver; return func() {}, nil },
		Findings: o}
	v, stop := StartWith(context.Background(), deps, func(f string, a ...any) { lmu.Lock(); logs = append(logs, f); lmu.Unlock() })
	defer stop()

	// Down: nothing is claimed, and past the bound each unanswered view is a finding.
	if _, err := v.State(AssignmentsRead); err == nil || !strings.Contains(err.Error(), "names no holder") {
		t.Fatalf("a state whose holder is not known is claimed: %v", err)
	}
	eventually(t, "no finding past the bound", func() bool { o.mu.Lock(); defer o.mu.Unlock(); return len(o.finds) == 2 })

	// Up: answered, the findings are cleared, and the pictures hold the owners' values.
	o.mu.Lock()
	o.down = false
	o.mu.Unlock()
	eventually(t, "not answered", func() bool { _, err := v.State(SeatHoldersRead); return err == nil })
	eventually(t, "findings not cleared", func() bool { o.mu.Lock(); defer o.mu.Unlock(); return len(o.finds) == 0 })
	if got, _ := v.Entry(AssignerSeat+".seat-holders", "none"); got != nil {
		t.Errorf("an absent key is %q", got)
	}

	// The catalog half is followed by the shared branch follower on the runner's own consumer: the gate's source names main,
	// main's view is adopted, and its entries are the modules, each with its manifest (design 47 G §196, §614).
	eventually(t, "the catalog half holds no modules", func() bool { m, err := v.Modules(); return err == nil && len(m) == 2 })
	m, _ := v.Modules()
	if m["web"].Manifest["module"] != "web" {
		t.Errorf("the module web is %+v", m["web"])
	}
	// A catalog-revision of the branch is heard on the same consumer and asks the view once more.
	o.mu.Lock()
	o.catalog, o.modules = 4, []string{"web", "db", fixtureHolder}
	o.mu.Unlock()
	ev, _ := json.Marshal(catalogseat.CatalogRevisionEvent{V: 1, Branch: "main", Kind: meshcatalogclient.KindTrunk, Revision: 4})
	if err := o.deliver(bus.Envelope{Key: catalogseat.Seat + "." + catalogseat.EventCatalogRevision, Body: ev}); err != nil {
		t.Fatal(err)
	}
	eventually(t, "the catalog-revision was not taken", func() bool { m, err := v.Modules(); return err == nil && len(m) == 3 })
	// And the halves by branch, with their revision, which mesh_wait names checking an emitter (design 34 every-event §14).
	if h, err := v.Halves(); err != nil || h["main"].Revision.Revision != 4 || len(h["main"].Entries) != 3 {
		t.Errorf("the halves: %+v, %v", h, err)
	}

	// Events: the next revision is applied; an old one passed over; a deletion removes; none of it asks again.
	asked := func(tool string) int { o.mu.Lock(); defer o.mu.Unlock(); return o.asked[tool] }
	before := asked("assignments")
	o.say(t, "assignments", "laptop", `{"p":2}`, 5, false)
	o.say(t, "assignments", "laptop", `{"p":0}`, 5, false)
	o.say(t, "assignments", "anchor", "", 6, false)
	// (a deleted mark carries no value: Deleted is the encoding's, set below)
	if got, _ := v.Entry(AssignerSeat+".assignments", "laptop"); string(got) != `{"p":2}` {
		t.Errorf("the next revision is not applied: %q", got)
	}
	if n := asked("assignments"); n != before {
		t.Errorf("an event in order asked the first view again (%d asks, was %d)", n, before)
	}

	// A gap (revision 9 where 7 was next) asks the first view once more, said in the log.
	o.say(t, "assignments", "x", `{"p":9}`, 9, false)
	eventually(t, "a gap did not ask the first view again", func() bool { return asked("assignments") > before })

	// The status says owner, tool, revision and the asks; the hand ask asks every view again.
	var assignments views.Status
	for _, s := range v.Status() {
		if s.State == "assignments" {
			assignments = s
		}
	}
	if assignments.Owner != fixtureHolder || assignments.Tool != "assignments" || assignments.Asks < 2 || assignments.Answered.IsZero() {
		t.Errorf("the status of assignments is %+v", assignments)
	}
	manifests := asked("seat-holders")
	if errs := v.Again(context.Background(), "doubted"); len(errs) != 0 {
		t.Fatalf("the hand ask failed: %v", errs)
	}
	if asked("seat-holders") != manifests+1 {
		t.Errorf("the hand ask did not ask the seat-holders again")
	}
	for _, st := range v.Status() {
		if st.State == "seat-holders" && st.ByHand != 1 {
			t.Errorf("the hand ask is not counted: %+v", st)
		}
	}
	lmu.Lock()
	defer lmu.Unlock()
	if !strings.Contains(strings.Join(logs, "\n"), "a gap in") {
		t.Errorf("the gap was not said in the log: %v", logs)
	}
}

// The four first views are the manifest's `consumes` families, and the console reads each by the name here.
func TestTheFirstViewsAreTheManifestsViews(t *testing.T) {
	raw, err := os.ReadFile("../../module.json")
	if err != nil {
		t.Fatal(err)
	}
	var m struct {
		Consumes []string `json:"consumes"`
	}
	if err := json.Unmarshal(raw, &m); err != nil {
		t.Fatal(err)
	}
	want := map[string]bool{AssignmentsRead: true, SeatHoldersRead: true}
	for _, s := range Specs {
		if !want[s.Name()] {
			t.Errorf("the first view %s is read by no name here", s.Name())
		}
		delete(want, s.Name())
		// the family is named by the seat, never by its holder (design 47 G §616)
		if view := "seat:" + AssignerSeat + ".views." + s.Tool; !slices.Contains(m.Consumes, view) {
			t.Errorf("the first view %s has no family in the manifest's consumes %v", view, m.Consumes)
		}
	}
	if len(want) > 0 {
		t.Errorf("no first view reads %v", want)
	}
	for _, c := range m.Consumes {
		if strings.Contains(c, "assigner") && !strings.HasPrefix(c, "seat:") {
			t.Errorf("the manifest names the assigner by a module: %s", c)
		}
	}
	// the catalog half's follower hears these events and asks these verbs, and the manifest says so (design 47 G §614)
	for _, ev := range []string{"mesh-catalog.catalog-revision", "mesh-catalog.registration-changed", "mesh-delivery.source-moved"} {
		if !slices.Contains(m.Consumes, ev) {
			t.Errorf("the catalog half's event %s is not in the manifest's consumes %v", ev, m.Consumes)
		}
	}
	for _, ev := range []string{"mesh-delivery-indexer.views.modules", "mesh-delivery-indexer.views.manifests"} {
		if slices.Contains(m.Consumes, ev) {
			t.Errorf("the manifest still consumes the indexer's %s", ev)
		}
	}
}

// design 47 G §616: the holder of the assigner seat is whichever module the catalog half says serves it; when another one
// claims it the views are of the new holder, and when none does the seat's names answer that the catalog half names no holder.
func TestTheAssignersViewsFollowTheModuleThatClaimsTheSeat(t *testing.T) {
	o := newOwners()
	deps := Deps{Module: "node-tools", Ask: o.ask, Bound: time.Second, Wait: 10 * time.Millisecond,
		Consume: func(deliver func(bus.Envelope) error) (func(), error) { o.deliver = deliver; return func() {}, nil }, Findings: o}
	v, stop := StartWith(context.Background(), deps, func(string, ...any) {})
	defer stop()
	eventually(t, "not answered", func() bool { _, err := v.State(AssignmentsRead); return err == nil })
	ownerOf := func() string {
		for _, s := range v.Status() {
			if s.State == "assignments" {
				return s.Owner
			}
		}
		return ""
	}
	if ownerOf() != fixtureHolder {
		t.Fatalf("the views are of %q", ownerOf())
	}
	revise := func(rev int64, holder string, modules ...string) {
		o.mu.Lock()
		o.catalog, o.modules, o.holder = rev, modules, holder
		o.mu.Unlock()
		ev, _ := json.Marshal(catalogseat.CatalogRevisionEvent{V: 1, Branch: "main", Kind: meshcatalogclient.KindTrunk, Revision: rev})
		if err := o.deliver(bus.Envelope{Key: catalogseat.Seat + "." + catalogseat.EventCatalogRevision, Body: ev}); err != nil {
			t.Fatal(err)
		}
	}
	revise(4, "other-holder", "web", "other-holder")
	eventually(t, "the views did not move to the new holder", func() bool { return ownerOf() == "other-holder" })
	eventually(t, "not answered", func() bool { _, err := v.State(SeatHoldersRead); return err == nil })
	revise(5, "", "web")
	eventually(t, "the views stayed after the claim went", func() bool {
		_, err := v.State(AssignmentsRead)
		return err != nil && strings.Contains(err.Error(), "names no holder")
	})
}